Spark Plugs

[D13 HPD 95]

Just done a monthly once over on the mk7 1.25 engine this morn and notice some water around my spark plugs but only on number 2 and 3 lifts the leads out and cleaned the plugs, the car didnt seem to be bothered if there was water within the leads tho, but the plug dont look great, probably since new plug after 32000 miles i have bought some new perfomance premium plugs, so how do i change them?? You have to check the spark gap dont you?? I dont have a clue how big it is or is meant to be. So is this just a garage jobby or DIY ?? I bought the plugs under they fit fiesta mk7 1.25 fine so does that mean the gap is the right size already??

Cheers

[craiglr]

the gap on the spark plug should be fine out of the box but just compare it to the plug you take out.

[D13 HPD 95]

Ok thank you

[stef123]

As above really, the gap should already be set if you bought them specifically for your engine but it has been known for them to be set incorrectly or even damaged in transit.

A quick check of them again the existing ones will give you an idea, although if the old ones are worn which they will be if they are 32K miles old you will be better with a gauge or feeler gauges to confirm

[mintalkin]

i always confirm that the plug gaps are correct before fitting, yours should be 1.3mm, also if your doing this job for the first time do one plug at a time you would be suprised how many people pull all the plugs leads off at once and then forget which plug they go on.

[D13 HPD 95]

Thank you, my leads are numbered so thats alright, and ill give it a go later on, might just leave it for the garage i dont have anything that will measure the gap apart from a school ruler lol

[craiglr]

seriosly dont worry about the gap size, ive never had to adjust one even when i used to work on cars. just have a look/compare it to the old one. its such an easy job just make sure you screw them in by hand as far as you can and then just nip them up not to tight.

[stef123]

seriosly dont worry about the gap size, ive never had to adjust one even when i used to work on cars. just have a look/compare it to the old one. its such an easy job just make sure you screw them in by hand as far as you can and then just nip them up not to tight.

Not a great bit of advice there considering you used to work on cars.

In the past I have had problems with the plug gaps being too large (1.3mm) and giving poor performance and economy. Reduced to 1.1 IIRC and problem solved. Too small a gap and you will also get problems.

Last year I had an Ibiza brought to me suffering with poor economy and performance. Engine was a 1.4 and should be doing mid 40s mpg, it was doing late 20s! First thing to check was the plugs, a gap of around 1.5mm! (I didn't measure it)

Car is now performing as it should and has been for about a year.

So yes, plug gap does matter. All I say is this, becareful of what advice you take from an Internet forum.if a job is worth doing, it's worth doing right - first time.

[D13 HPD 95]

Thanks for the help, ill just ask my garage to

Change them when i go for the service cheers

[craiglr]

well ive personally never seen a spark plug with wrong gap size and i gaurentee nearly all garages don't even check the plug gap.

i didnt actually mean the gap size doesn't matter i just meant i wouldn't worry to much about it aslong as it looks the same as old one.